Attachment for sewing machines



Dec. 12, 1950 P. J. STUSTER 2,533,746

ATTACHMENT FOR SEWING MACHINES Filed NOV. 1, 1948 INVENTOR Philip J.Stuster ATTORNE Patented Dec. 12, 1950 U N I T E D S TATE S PATEN T PF!CE ATTACHMENT FOR SEWING MACHINES Philip J. Stuster, Huntington Park,Galif.

Application'November 1, 1948 'Serial'No. 57,694

"The present invention relates "generally to attachments for sewingmachines, and more especially to attachments which provide means foradjusting or regulating the pressure applied to the work by the presserbar.

This is especially f b'eing handled, the pull of the thread, or variousother factors encountered in sewing.

There have been some attachments devised for this purpose, but so far asknown these have not been entirely satisfactory. For example, a devicewhich permits only a maximum or minimum pressure is not satisfactorybecause it does lnotfafford enough variations in pressure. Other deviceshave not been positive in their action, that is they cannot be reliedupon to maintain a definite Setting after adjustment, or else they aretoo slow and difficult to manipulate to provide the desired variation.Devices of this latter class are of very little value since the machineoperator cannot take the "time to change the settings, especially whenmany'frequent changes :are desired.

Hence it becomes .a general object of "my invention to provide anattachment for a sew- 'ing machine which enables a wide selection ofpressures to be exerted by the ipresser bar and ,jpress'er 'Ioot.

It is also another object of .my invention to provide an attachment ofthis character which is positive in its operation and is adapted "tojl'emain securely in any "adjusted position.

It is a further object of my invention to provide an attachment of thischaracter which is not only simple in its manufacture andconstruction,but is also quick and easy of manipula- 'jti'on so that themachine operator can obtain any desired setting with a minimum of timeand so obtain a maximum amount of benefit from the attachment.

I have attained these and other objects in a pressure regulatorconstructed according to my invention by providing a sleeve which isslidably mounted on the upper end of the conventional presser bar withthe lower end of the sleeve'bearing against the upper end of theconventional compression spring.

is usually a coil spring which surrounds the This spring presser bar andbears at its lower end against a 27 Claims. (01. 11.-223'6f) transversemember attached to the presser bar so "that the compressive *forceexerted by the spring is transmit-ted to the presser bar and' to thefoot onthe 'lower end of the bar. A collar surrounding at least .a partof the sleeve i's -held stationary by engagement with the frame ot thesewing machine. The external surface of 'the'sleeve is serrated in amanner to provide a pression of the spring and hence increase the forceon the presser'bar.

How the above objects and advantages of my invention, as well as othersnot specifically :mention'ed herein, are attained will be more fully andreadily understood by reference to the $01- I lowing description, and tothe annexed drawings,

:in which:

Fig. '1 is an end elevation of a conventional type of sewing machinewith .a portion of the end cover plate broken away in order *to show thepresser bar and associated spring, ta pressure regulator constructedaccording to my inven- 'tion being "mounted on the upper end of thepresser bar; "Fig. 2 is a fragmentary vertical section taken on line2-'2 of Fig. 1';

Fig. '3 is a horizontal section through the pressure regulator taken online 3-3 of Fig.1; :and

liig. 4 is a fragmentary elevation of 1a variational form of sleeve fortheir-regulator.

Fig. '1 shows 'in elevation the end of a conventional type of sewingmachine comprising a frame Iii on which the end cover plate 12 has beenpartially broken away in order to show the pertinent parts of theinterior mechanism. Mounted for vertical reciprocation in machine frameit, is needle bar 14 and presser bar 315 which carries on its lower endpresser foot "16 which-is associated with needle t? on the lower "endofneedle bar 44.

' At a point intermediate its ends, presser bar I 5 has attached to ita'transverse bar 2553 against which bears the lower end of @011 spring212 which is mounted on the presser bar. The presserlbar may be liftedand held in raised position by means of cam handle 24 pivotally mountedon the machine frame and provided with cam 25 which engages the underside of transverse bar 20 to lift the presser bar when handle 24 islifted or rotated clockwise as viewed in the figure. The mechanism sofar described is conventional and well known and forms no part of thepresent invention. It is described here in order that my invention, aswell as its application to'a sewing machine, may be more fullyunderstood.

The pressure regulator, or darning attachment, as it is sometimescalled, is mounted on the machine at the upper end of the presser barand is generally indicated in the drawings at 26. It consists of anouter hollow collar 28 which is threaded at its lower end so that it canbe screwed into a suitable threaded bore 29 in machine frame III, asshown best in Fig. 2. Collar 28 receives with a loose sliding fit sleeve31] which is also hollow and is slidable on the upper end of presser barIS with the lower end of the sleeve bearing against the upper end ofspring 22 around the presser bar. The sleeve is here shown as beingdirectly in contact with spring 22 but a washer or the like may beinserted if desired between the Any ', Spring 22 is normally maintainedunder cornpression between sleeve 3!) and transverse bar 20, thecompressive force exerted by the spring being transmitted to the presserbar through the connection of transverse member 29 to the presser bar.Naturally the spring pressing against the lower end of sleeve 39 urgesit upwardly; and in order to maintain compression on the spring it isnecessary to provide means for holding the -'sleeve and collar againstrelative movement in order to maintain the compression on the spring.For this purpose, the upper part of the external surface of sleeve 33 isserrated in such a manner as to produce a longitudinally spaced seriesof "teethJhaVing upwardly facing and radially extending surfaces. Thisis done preferably by proyiding the sleeve with a plurality ofcircumferential ridges 32 each of which has an upper face 33 that facesupwardly and is substantially radial or normal to the length of collar30, and a lower inclined face 34 which is inclined downwardly andinwardly toward the axis of the sleeve. The number of these ridges, andhence the spacing between successive surfaces 33, may be as much or aslittle as desired, but I find it convenient and satisfactory to provideabout six such faces within the normal travel of sleeve 30.

There is provided on collar 28 latch means which is engageable with anyselected one of the several faces 33 and which is adapted, by suchengagement, to hold the sleeve in a selected position against the upwardmovement induced by spring 22. This latch means is shown best in Fig. 3,and comprises lever 36 pivotally mounted i on the collar by pin 31. Thelever is bent or curved and is located partly in slot 38 which extendsthrough the collar wall for a fraction of its periphery. Lever 36 isprovided at one end with an inwardly projecting lug 360. which can 4 bemoved into position to engage any one of the radial surfaces 33. Theother end of the lever is provided with a handle 361) by means of whichthe lever can be manually manipulated.

Latch as is normally urged toward the position of Fig. 3, in which itengages sleeve 30', by means of wire spring 40 which is fastened tocollar 28 at one end and at the other end seats in. a notch in lever 33opposite lug 36a.

The operation of the device will be readily apparent from the foregoingdescription and the drawings. When the machine operator manuallydepresses sleeve 30, spring 22 is compressed and a correspondinglygreater force is exerted on presser bar l5. At any position in which oneof the radial faces 33 engages the under side of lever 36, the latchholds the sleeve against upward movement relative to the presser bar andcollar 28; and the amount of compression in spring 22 depends upon howfar the sleeve has been depressed or which one of the radial faces is inengagement with the latch means.

If the end 36b of the latch lever is manually pressed toward th collar,the other end moves out of engagement with the radial faces on thesleeve and the s eeve is then free to move within collar 28 relative tothe collar and the presser bar. While the latch is in its normal orengaging position, as shown in Fig. 3, the collar can be moveddownwardly without manual manipulation of the latch means by simplypressing on the upper end of the sleeve. Downward movement of the sleevecauses a downwardly facing inclined surface 34 to engage projection 33aand, by cam action, to move the latch lever outward-a sufficientdistance to allow the sleeve to move down at least to the next radialface. At all times spring 40 urges projection 36a inwardly toward asleeve-engaging position so that the sleeve is immediately engaged andheld in any adjusted position when downward pressure on it is released.

I have described above a form in which circumferential ridges 32 provideone form of a series of longitudinally spaced shoulder means. 01)-viously the ridges can be made as a spiral or screw thread as shown at32a in Fig. 4. The faces are still radial and are in an axially spacedrow, when viewed in section, but havea slight tilt that can becompensated for by incliningjproj'ection 360. on the latch means. I

From the foregoing description of a preferred embodiment of my inventionit will be evident that various changes in the construction ,may be madeby persons skilled in the art without departing from the spirit andscope of my inven tion; and consequently I wish it understood that theforegoing description is considered as being illustrative of, ratherthan limitative upon, the appended claims.

I claim:

1. A pressure regulator for a presser bar assembly having a compressionspring that forces the presser bar downwardly, comprising: a stationarycollar; a sleeve slidable within the collar and bearing against theupper end of the spring, the sleeve having a plurality of axially spacedradially extending external faces; and latch means carried on the collarengageable with a selected radial face to hold the sleeve againstrelative upward movement.

2. A pressure regulator as in claim 1 in which the latch means ismanually disengageable from the sleeve faces to permit freemovement ofthe I sleeve, and also includes spring means normally urging the latchmeans toward the face enaging position.

3. A pressure regulator for a presser bar assembly having a compressionspring that forces the presser bar downwardly, comprising: a stationarycollar; a sleeve slidably carried by the collar and bearing against theupper end of the spring, the sleeve having a plurality of axially spacedcircumferential ridges each of which has an upper radial face and alower inclined face; and latch means carried on the collar engageablewith a selected radial face to hold the sleeve against relative upwardmovement, the latch means being retractable by engagement with aninclined face during downward movement of the sleeve to increase thespring compression.

4. A pressure regulator for a presser bar assembly having a compressionspring that forces the presser bar downwardly, comprising: a stationarycollar; a sleeve slidably carried by the collar and bearing against theupper end of the spring, the sleeve having a plurality of axially spacedradially extending external faces; a latch member pivotally mounted onthe collar and movable into engagement at one end with a selected radialface to hold the sleeve against upward movement; and a spring normallyurging the latch into said engagement.

5. A pressure regulator for a presser bar assembly having a compressionspring that forces the presser bar downwardly, comprising: a stationarycollar; a sleeve slidably carried by the collar and bearing against theupper end of the spring, the sleeve having an external spiral ridgeforming an axial row of spaced radially extending faces; and latch meanscarried on the collar engageable with a selected radial face to hold thesleeve against relative upward movement.

6. In means for varying the pressure imposed upon the presser foot of asewing machine having a head, said foot being carried upon the lower endof a presser bar of which the upper end is longitudinally movable insaid head under the pressure of a spring thereon, the combinationcomprising: a stationary collar adapted to be fixed upon said sewingmachine head; an inwardly projecting member carried on the collar; and asleeve slidably carried on said collar and provided with a plurality oflongitudinally spaced shoulder means selectively engageable with saidinwardly projecting member to lock the sleeve in any one of a pluralityof predetermined positions intermediate the extremes of its slidablemovement in opposite directions to place said spring undercorrespondingly different compressions.

'7. In means for varying the pressure imposed upon the presser foot of asewing machine having a head, said foot being carried upon the lower endof a presser bar of which the upper end is vertically movable in saidhead under the pressure of a spring thereon, the combination comprising:a stationary collar adapted to be fixed upon said sewing machine head; asleeve slidably carried by said collar for movement to a plurality ofintermediate positions between the extremes of its slidable movement inopposite directions to place said spring under correspondingly differentcompressions, said sleeve having a plurality of shoulder means spacedapart in the direction of sliding movement; and a lock member carried onthe collar and engageable with a selected one of said shoulder means forholding the sleeve in any of said intermediate positions of adjustment.

PHILIP J. STUSTER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Numer Name Date 2,012,157 Corson Aug. 20, 19352,193,098 Huenergarde Mar. 12, 1940

